This invention relates generally to security devices and more particularly to portable devices.
Most thefts within a building are committed by internal personnel. These thefts are usually minor in cost in that small items are stolen. This type of theft is particularly difficult to solve since many different people had access to the location including cleaning personnel, co-workers, security personnel, and others.
In the field of industrial espionage, the theft itself might be undetectable since no physical items are removed, only the data, plans, layouts, or other proprietary material.
The first step in solving this type of crime is limit the number of suspects. That is, it is not feasible to consider all personnel who might have had access to the information or item. As noted earlier, this would include almost everyone from the cleaning crew to the security personnel.
To address this problem, there have been many proposed solutions including that described by U.S. Pat. No. 4,476,461 entitled "Occupancy Monitor", issued to Carubia on Oct. 9, 1984. In Carubia, a plurality of switches are spread throughout the building and by analyzing their activation, it is possible to determine if a specific room is occupied.
The Carubia system is "hard-wired" into the building and as such is static. That is, once the location of these switches are identified, by the cleaning personnel or co-workers, it is child's play to avoid them when entering the room. Carubia does not allow for changing of the pattern of detectors nor does it provide any simple means to protect new additions to the building.
Additionally, Carubia can be easily confused by the mere activation of a switch. That is by activating the switch upon the entry within the room and then providing a "false" entry by merely activating the switch again, it will appear to the computer that a person "accidentally" entered the room, realized his/her mistake, and instantly left the room. No cause for alarm, yet the intruder still remains within the room.
Another solution to the problem is proposed by Hughes in his patent entitled "Door Actuated Time Recorder", U.S. Pat. No. 3,792,493, issued Feb. 12, 1974. Hughes, as did Carubia, relies upon an elaborate and fixed system to provide security. As with Carubia, Hughes assumes that two signals from a door site indicate that a person entered and then left. As shown earlier, this is not always true.
Other inventions which have focused their attention on the activation of a door, include U.S. Pat. No. 2,051,986, entitled "Door Recorder" and issued to Cool on Aug. 25, 1936, and U.S. Pat. No. 2,621,998, issued to Lewis on Dec. 16, 1952. As noted earlier, these door-affixed measurements can be easily fooled and more importantly, are fixed so that their presence can be detected by the intruder and circumvented.
Another variation of monitoring the door, is to monitor the lock associated with the door. This was done in "Time Recorder for Locks" by Pullman, U.S. Pat. No. 1,452,846, issued Apr. 24, 1923. Again the fixed nature of the device together with its ability to be easily fooled, make the device totally unsuitable.
A fixed security system is particularly vulnerable to circumvention. These concerns are espoused in U.S. Pat. No. 4,015,256, "Electronic Control Unit for Intrusion System", issued to Pratt on Mar. 29, 1977. Pratt was so concerned with tampering with the control panel, that "the control center" is "hermetically encapsulated in a mass of hard plastic" (abstract).
Security extends past the ability to secure a room. The security for items stored within a drawer or filing cabinet are equally important. This application is impossible for either Carubia or Hughes to address due to their size, complexity, and the inability to address moveable items such as desks.
One solution which has been posed for securing desk drawers and the like is presented by Shew in U.S. Pat. No. 3,631,445, entitled "Burglar Alarm and Locking Device for Drawer", issued Dec. 28, 1971. Shew's device is a complex arrangement of locks and sensors which fits within the desk behind the drawer. Should an attempt to open the drawer be made without first using a key, then an alarm is sounded and a gripping mechanism prevents the drawer from being forced open.
The Shew device is designed for the few high-security drawers found within most offices. Because of its cost, complexity in use, and reduction in the drawer space, it is totally inappropriate for most drawers where a purse, loose change, or a calculator is kept. In this situation, the owner of the purse does not wish to have to continuously unlock the drawer for access to the purse.
Additionally, the Shew device is incapable of being moved. Once it is placed within the desk, it is permanently affixed and cannot be moved. Its very nature and use of the sensors prevent its removal.
Although some of the prior solutions are useful for their intended purpose, they all suffer due their basic concept. That is, they are intended to provide absolute security against theft. Although this is a problem, absolute security is much too costly to implement for everything (i.e. locking a calculator up at night requires too much capital equipment and manpower). Most items within a plant are "secured" by the thief's fear that he will be caught. Hence, the items which are locked away, although safe, are not of interest, what the thief is attracted to are the items which do not require the highest level of security such as cameras, calculators, desk-top computers. In the intelligence area, this would include general memos, letters, trashed spread sheets, and the like.
It is clear from the forgoing, that a system has not been generated with will assist in securing the vast majority of items.